Find common elements In 3 sorted arrays in Python

def find_common_elements(arr1, arr2, arr3):
i = j = k = 0
common = []

while i < len(arr1) and j < len(arr2) and k < len(arr3):
# If all three are equal
if arr1[i] == arr2[j] == arr3[k]:
if not common or common[-1] != arr1[i]: # Avoid duplicates
common.append(arr1[i])
i += 1
j += 1
k += 1
# Find the smallest and move its pointer forward
elif arr1[i] < arr2[j]:
i += 1
elif arr2[j] < arr3[k]:
j += 1
else:
k += 1

return common